xref: /openbmc/linux/drivers/iio/adc/bcm_iproc_adc.c (revision be709d48)
1 /*
2  * Copyright 2016 Broadcom
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License, version 2, as
6  * published by the Free Software Foundation (the "GPL").
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License version 2 (GPLv2) for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * version 2 (GPLv2) along with this source code.
15  */
16 
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/io.h>
20 #include <linux/clk.h>
21 #include <linux/mfd/syscon.h>
22 #include <linux/regmap.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/platform_device.h>
26 
27 #include <linux/iio/iio.h>
28 
29 /* Below Register's are common to IPROC ADC and Touchscreen IP */
30 #define IPROC_REGCTL1			0x00
31 #define IPROC_REGCTL2			0x04
32 #define IPROC_INTERRUPT_THRES		0x08
33 #define IPROC_INTERRUPT_MASK		0x0c
34 #define IPROC_INTERRUPT_STATUS		0x10
35 #define IPROC_ANALOG_CONTROL		0x1c
36 #define IPROC_CONTROLLER_STATUS		0x14
37 #define IPROC_AUX_DATA			0x20
38 #define IPROC_SOFT_BYPASS_CONTROL	0x38
39 #define IPROC_SOFT_BYPASS_DATA		0x3C
40 
41 /* IPROC ADC Channel register offsets */
42 #define IPROC_ADC_CHANNEL_REGCTL1		0x800
43 #define IPROC_ADC_CHANNEL_REGCTL2		0x804
44 #define IPROC_ADC_CHANNEL_STATUS		0x808
45 #define IPROC_ADC_CHANNEL_INTERRUPT_STATUS	0x80c
46 #define IPROC_ADC_CHANNEL_INTERRUPT_MASK	0x810
47 #define IPROC_ADC_CHANNEL_DATA			0x814
48 #define IPROC_ADC_CHANNEL_OFFSET		0x20
49 
50 /* Bit definitions for IPROC_REGCTL2 */
51 #define IPROC_ADC_AUXIN_SCAN_ENA	BIT(0)
52 #define IPROC_ADC_PWR_LDO		BIT(5)
53 #define IPROC_ADC_PWR_ADC		BIT(4)
54 #define IPROC_ADC_PWR_BG		BIT(3)
55 #define IPROC_ADC_CONTROLLER_EN		BIT(17)
56 
57 /* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
58 #define IPROC_ADC_AUXDATA_RDY_INTR	BIT(3)
59 #define IPROC_ADC_INTR			9
60 #define IPROC_ADC_INTR_MASK		(0xFF << IPROC_ADC_INTR)
61 
62 /* Bit definitions for IPROC_ANALOG_CONTROL */
63 #define IPROC_ADC_CHANNEL_SEL		11
64 #define IPROC_ADC_CHANNEL_SEL_MASK	(0x7 << IPROC_ADC_CHANNEL_SEL)
65 
66 /* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
67 #define IPROC_ADC_CHANNEL_ROUNDS	0x2
68 #define IPROC_ADC_CHANNEL_ROUNDS_MASK	(0x3F << IPROC_ADC_CHANNEL_ROUNDS)
69 #define IPROC_ADC_CHANNEL_MODE		0x1
70 #define IPROC_ADC_CHANNEL_MODE_MASK	(0x1 << IPROC_ADC_CHANNEL_MODE)
71 #define IPROC_ADC_CHANNEL_MODE_TDM	0x1
72 #define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
73 #define IPROC_ADC_CHANNEL_ENABLE	0x0
74 #define IPROC_ADC_CHANNEL_ENABLE_MASK	0x1
75 
76 /* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
77 #define IPROC_ADC_CHANNEL_WATERMARK	0x0
78 #define IPROC_ADC_CHANNEL_WATERMARK_MASK \
79 		(0x3F << IPROC_ADC_CHANNEL_WATERMARK)
80 
81 #define IPROC_ADC_WATER_MARK_LEVEL	0x1
82 
83 /* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
84 #define IPROC_ADC_CHANNEL_DATA_LOST		0x0
85 #define IPROC_ADC_CHANNEL_DATA_LOST_MASK	\
86 		(0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
87 #define IPROC_ADC_CHANNEL_VALID_ENTERIES	0x1
88 #define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK	\
89 		(0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
90 #define IPROC_ADC_CHANNEL_TOTAL_ENTERIES	0x9
91 #define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK	\
92 		(0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)
93 
94 /* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
95 #define IPROC_ADC_CHANNEL_WTRMRK_INTR			0x0
96 #define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK		\
97 		(0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
98 #define IPROC_ADC_CHANNEL_FULL_INTR			0x1
99 #define IPROC_ADC_CHANNEL_FULL_INTR_MASK		\
100 		(0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
101 #define IPROC_ADC_CHANNEL_EMPTY_INTR			0x2
102 #define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK		\
103 		(0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)
104 
105 #define IPROC_ADC_WATER_MARK_INTR_ENABLE		0x1
106 
107 /* Number of time to retry a set of the interrupt mask reg */
108 #define IPROC_ADC_INTMASK_RETRY_ATTEMPTS		10
109 
110 #define IPROC_ADC_READ_TIMEOUT        (HZ*2)
111 
112 #define iproc_adc_dbg_reg(dev, priv, reg) \
113 do { \
114 	u32 val; \
115 	regmap_read(priv->regmap, reg, &val); \
116 	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
117 } while (0)
118 
119 struct iproc_adc_priv {
120 	struct regmap *regmap;
121 	struct clk *adc_clk;
122 	struct mutex mutex;
123 	int  irqno;
124 	int chan_val;
125 	int chan_id;
126 	struct completion completion;
127 };
128 
129 static void iproc_adc_reg_dump(struct iio_dev *indio_dev)
130 {
131 	struct device *dev = &indio_dev->dev;
132 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
133 
134 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL1);
135 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL2);
136 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_THRES);
137 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_MASK);
138 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_STATUS);
139 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_CONTROLLER_STATUS);
140 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_ANALOG_CONTROL);
141 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_AUX_DATA);
142 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_CONTROL);
143 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_DATA);
144 }
145 
146 static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data)
147 {
148 	u32 channel_intr_status;
149 	u32 intr_status;
150 	u32 intr_mask;
151 	struct iio_dev *indio_dev = data;
152 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
153 
154 	/*
155 	 * This interrupt is shared with the touchscreen driver.
156 	 * Make sure this interrupt is intended for us.
157 	 * Handle only ADC channel specific interrupts.
158 	 */
159 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
160 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &intr_mask);
161 	intr_status = intr_status & intr_mask;
162 	channel_intr_status = (intr_status & IPROC_ADC_INTR_MASK) >>
163 				IPROC_ADC_INTR;
164 	if (channel_intr_status)
165 		return IRQ_WAKE_THREAD;
166 
167 	return IRQ_NONE;
168 }
169 
170 static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data)
171 {
172 	irqreturn_t retval = IRQ_NONE;
173 	struct iproc_adc_priv *adc_priv;
174 	struct iio_dev *indio_dev = data;
175 	unsigned int valid_entries;
176 	u32 intr_status;
177 	u32 intr_channels;
178 	u32 channel_status;
179 	u32 ch_intr_status;
180 
181 	adc_priv = iio_priv(indio_dev);
182 
183 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
184 	dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_handler(),INTRPT_STS:%x\n",
185 			intr_status);
186 
187 	intr_channels = (intr_status & IPROC_ADC_INTR_MASK) >> IPROC_ADC_INTR;
188 	if (intr_channels) {
189 		regmap_read(adc_priv->regmap,
190 			    IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
191 			    IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
192 			    &ch_intr_status);
193 
194 		if (ch_intr_status & IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK) {
195 			regmap_read(adc_priv->regmap,
196 					IPROC_ADC_CHANNEL_STATUS +
197 					IPROC_ADC_CHANNEL_OFFSET *
198 					adc_priv->chan_id,
199 					&channel_status);
200 
201 			valid_entries = ((channel_status &
202 				IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK) >>
203 				IPROC_ADC_CHANNEL_VALID_ENTERIES);
204 			if (valid_entries >= 1) {
205 				regmap_read(adc_priv->regmap,
206 					IPROC_ADC_CHANNEL_DATA +
207 					IPROC_ADC_CHANNEL_OFFSET *
208 					adc_priv->chan_id,
209 					&adc_priv->chan_val);
210 				complete(&adc_priv->completion);
211 			} else {
212 				dev_err(&indio_dev->dev,
213 					"No data rcvd on channel %d\n",
214 					adc_priv->chan_id);
215 			}
216 			regmap_write(adc_priv->regmap,
217 					IPROC_ADC_CHANNEL_INTERRUPT_MASK +
218 					IPROC_ADC_CHANNEL_OFFSET *
219 					adc_priv->chan_id,
220 					(ch_intr_status &
221 					~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK)));
222 		}
223 		regmap_write(adc_priv->regmap,
224 				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
225 				IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
226 				ch_intr_status);
227 		regmap_write(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
228 				intr_channels);
229 		retval = IRQ_HANDLED;
230 	}
231 
232 	return retval;
233 }
234 
235 static int iproc_adc_do_read(struct iio_dev *indio_dev,
236 			   int channel,
237 			   u16 *p_adc_data)
238 {
239 	int read_len = 0;
240 	u32 val;
241 	u32 mask;
242 	u32 val_check;
243 	int failed_cnt = 0;
244 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
245 
246 	mutex_lock(&adc_priv->mutex);
247 
248 	/*
249 	 * After a read is complete the ADC interrupts will be disabled so
250 	 * we can assume this section of code is safe from interrupts.
251 	 */
252 	adc_priv->chan_val = -1;
253 	adc_priv->chan_id = channel;
254 
255 	reinit_completion(&adc_priv->completion);
256 	/* Clear any pending interrupt */
257 	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
258 			IPROC_ADC_INTR_MASK | IPROC_ADC_AUXDATA_RDY_INTR,
259 			((0x0 << channel) << IPROC_ADC_INTR) |
260 			IPROC_ADC_AUXDATA_RDY_INTR);
261 
262 	/* Configure channel for snapshot mode and enable  */
263 	val = (BIT(IPROC_ADC_CHANNEL_ROUNDS) |
264 		(IPROC_ADC_CHANNEL_MODE_SNAPSHOT << IPROC_ADC_CHANNEL_MODE) |
265 		(0x1 << IPROC_ADC_CHANNEL_ENABLE));
266 
267 	mask = IPROC_ADC_CHANNEL_ROUNDS_MASK | IPROC_ADC_CHANNEL_MODE_MASK |
268 		IPROC_ADC_CHANNEL_ENABLE_MASK;
269 	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL1 +
270 				IPROC_ADC_CHANNEL_OFFSET * channel),
271 				mask, val);
272 
273 	/* Set the Watermark for a channel */
274 	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL2 +
275 					IPROC_ADC_CHANNEL_OFFSET * channel),
276 					IPROC_ADC_CHANNEL_WATERMARK_MASK,
277 					0x1);
278 
279 	/* Enable water mark interrupt */
280 	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_INTERRUPT_MASK +
281 					IPROC_ADC_CHANNEL_OFFSET *
282 					channel),
283 					IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK,
284 					IPROC_ADC_WATER_MARK_INTR_ENABLE);
285 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val);
286 
287 	/* Enable ADC interrupt for a channel */
288 	val |= (BIT(channel) << IPROC_ADC_INTR);
289 	regmap_write(adc_priv->regmap, IPROC_INTERRUPT_MASK, val);
290 
291 	/*
292 	 * There seems to be a very rare issue where writing to this register
293 	 * does not take effect.  To work around the issue we will try multiple
294 	 * writes.  In total we will spend about 10*10 = 100 us attempting this.
295 	 * Testing has shown that this may loop a few time, but we have never
296 	 * hit the full count.
297 	 */
298 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
299 	while (val_check != val) {
300 		failed_cnt++;
301 
302 		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS)
303 			break;
304 
305 		udelay(10);
306 		regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
307 				IPROC_ADC_INTR_MASK,
308 				((0x1 << channel) <<
309 				IPROC_ADC_INTR));
310 
311 		regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
312 	}
313 
314 	if (failed_cnt) {
315 		dev_dbg(&indio_dev->dev,
316 			"IntMask failed (%d times)", failed_cnt);
317 		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS) {
318 			dev_err(&indio_dev->dev,
319 				"IntMask set failed. Read will likely fail.");
320 			read_len = -EIO;
321 			goto adc_err;
322 		};
323 	}
324 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
325 
326 	if (wait_for_completion_timeout(&adc_priv->completion,
327 		IPROC_ADC_READ_TIMEOUT) > 0) {
328 
329 		/* Only the lower 16 bits are relevant */
330 		*p_adc_data = adc_priv->chan_val & 0xFFFF;
331 		read_len = sizeof(*p_adc_data);
332 
333 	} else {
334 		/*
335 		 * We never got the interrupt, something went wrong.
336 		 * Perhaps the interrupt may still be coming, we do not want
337 		 * that now.  Lets disable the ADC interrupt, and clear the
338 		 * status to put it back in to normal state.
339 		 */
340 		read_len = -ETIMEDOUT;
341 		goto adc_err;
342 	}
343 	mutex_unlock(&adc_priv->mutex);
344 
345 	return read_len;
346 
347 adc_err:
348 	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
349 			   IPROC_ADC_INTR_MASK,
350 			   ((0x0 << channel) << IPROC_ADC_INTR));
351 
352 	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
353 			   IPROC_ADC_INTR_MASK,
354 			   ((0x0 << channel) << IPROC_ADC_INTR));
355 
356 	dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n");
357 	iproc_adc_reg_dump(indio_dev);
358 	mutex_unlock(&adc_priv->mutex);
359 
360 	return read_len;
361 }
362 
363 static int iproc_adc_enable(struct iio_dev *indio_dev)
364 {
365 	u32 val;
366 	u32 channel_id;
367 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
368 	int ret;
369 
370 	/* Set i_amux = 3b'000, select channel 0 */
371 	ret = regmap_update_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
372 				IPROC_ADC_CHANNEL_SEL_MASK, 0);
373 	if (ret) {
374 		dev_err(&indio_dev->dev,
375 			"failed to write IPROC_ANALOG_CONTROL %d\n", ret);
376 		return ret;
377 	}
378 	adc_priv->chan_val = -1;
379 
380 	/*
381 	 * PWR up LDO, ADC, and Band Gap (0 to enable)
382 	 * Also enable ADC controller (set high)
383 	 */
384 	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
385 	if (ret) {
386 		dev_err(&indio_dev->dev,
387 			"failed to read IPROC_REGCTL2 %d\n", ret);
388 		return ret;
389 	}
390 
391 	val &= ~(IPROC_ADC_PWR_LDO | IPROC_ADC_PWR_ADC | IPROC_ADC_PWR_BG);
392 
393 	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
394 	if (ret) {
395 		dev_err(&indio_dev->dev,
396 			"failed to write IPROC_REGCTL2 %d\n", ret);
397 		return ret;
398 	}
399 
400 	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
401 	if (ret) {
402 		dev_err(&indio_dev->dev,
403 			"failed to read IPROC_REGCTL2 %d\n", ret);
404 		return ret;
405 	}
406 
407 	val |= IPROC_ADC_CONTROLLER_EN;
408 	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
409 	if (ret) {
410 		dev_err(&indio_dev->dev,
411 			"failed to write IPROC_REGCTL2 %d\n", ret);
412 		return ret;
413 	}
414 
415 	for (channel_id = 0; channel_id < indio_dev->num_channels;
416 		channel_id++) {
417 		ret = regmap_write(adc_priv->regmap,
418 				IPROC_ADC_CHANNEL_INTERRUPT_MASK +
419 				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
420 		if (ret) {
421 			dev_err(&indio_dev->dev,
422 			    "failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
423 			    ret);
424 			return ret;
425 		}
426 
427 		ret = regmap_write(adc_priv->regmap,
428 				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
429 				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
430 		if (ret) {
431 			dev_err(&indio_dev->dev,
432 			    "failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
433 			    ret);
434 			return ret;
435 		}
436 	}
437 
438 	return 0;
439 }
440 
441 static void iproc_adc_disable(struct iio_dev *indio_dev)
442 {
443 	u32 val;
444 	int ret;
445 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
446 
447 	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
448 	if (ret) {
449 		dev_err(&indio_dev->dev,
450 			"failed to read IPROC_REGCTL2 %d\n", ret);
451 		return;
452 	}
453 
454 	val &= ~IPROC_ADC_CONTROLLER_EN;
455 	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
456 	if (ret) {
457 		dev_err(&indio_dev->dev,
458 			"failed to write IPROC_REGCTL2 %d\n", ret);
459 		return;
460 	}
461 }
462 
463 static int iproc_adc_read_raw(struct iio_dev *indio_dev,
464 			  struct iio_chan_spec const *chan,
465 			  int *val,
466 			  int *val2,
467 			  long mask)
468 {
469 	u16 adc_data;
470 	int err;
471 
472 	switch (mask) {
473 	case IIO_CHAN_INFO_RAW:
474 		err =  iproc_adc_do_read(indio_dev, chan->channel, &adc_data);
475 		if (err < 0)
476 			return err;
477 		*val = adc_data;
478 		return IIO_VAL_INT;
479 	case IIO_CHAN_INFO_SCALE:
480 		switch (chan->type) {
481 		case IIO_VOLTAGE:
482 			*val = 1800;
483 			*val2 = 10;
484 			return IIO_VAL_FRACTIONAL_LOG2;
485 		default:
486 			return -EINVAL;
487 		}
488 	default:
489 		return -EINVAL;
490 	}
491 }
492 
493 static const struct iio_info iproc_adc_iio_info = {
494 	.read_raw = &iproc_adc_read_raw,
495 };
496 
497 #define IPROC_ADC_CHANNEL(_index, _id) {                \
498 	.type = IIO_VOLTAGE,                            \
499 	.indexed = 1,                                   \
500 	.channel = _index,                              \
501 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
502 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
503 	.datasheet_name = _id,                          \
504 }
505 
506 static const struct iio_chan_spec iproc_adc_iio_channels[] = {
507 	IPROC_ADC_CHANNEL(0, "adc0"),
508 	IPROC_ADC_CHANNEL(1, "adc1"),
509 	IPROC_ADC_CHANNEL(2, "adc2"),
510 	IPROC_ADC_CHANNEL(3, "adc3"),
511 	IPROC_ADC_CHANNEL(4, "adc4"),
512 	IPROC_ADC_CHANNEL(5, "adc5"),
513 	IPROC_ADC_CHANNEL(6, "adc6"),
514 	IPROC_ADC_CHANNEL(7, "adc7"),
515 };
516 
517 static int iproc_adc_probe(struct platform_device *pdev)
518 {
519 	struct iproc_adc_priv *adc_priv;
520 	struct iio_dev *indio_dev = NULL;
521 	int ret;
522 
523 	indio_dev = devm_iio_device_alloc(&pdev->dev,
524 					sizeof(*adc_priv));
525 	if (!indio_dev) {
526 		dev_err(&pdev->dev, "failed to allocate iio device\n");
527 		return -ENOMEM;
528 	}
529 
530 	adc_priv = iio_priv(indio_dev);
531 	platform_set_drvdata(pdev, indio_dev);
532 
533 	mutex_init(&adc_priv->mutex);
534 
535 	init_completion(&adc_priv->completion);
536 
537 	adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
538 			   "adc-syscon");
539 	if (IS_ERR(adc_priv->regmap)) {
540 		dev_err(&pdev->dev, "failed to get handle for tsc syscon\n");
541 		ret = PTR_ERR(adc_priv->regmap);
542 		return ret;
543 	}
544 
545 	adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
546 	if (IS_ERR(adc_priv->adc_clk)) {
547 		dev_err(&pdev->dev,
548 			"failed getting clock tsc_clk\n");
549 		ret = PTR_ERR(adc_priv->adc_clk);
550 		return ret;
551 	}
552 
553 	adc_priv->irqno = platform_get_irq(pdev, 0);
554 	if (adc_priv->irqno <= 0) {
555 		dev_err(&pdev->dev, "platform_get_irq failed\n");
556 		ret = -ENODEV;
557 		return ret;
558 	}
559 
560 	ret = regmap_update_bits(adc_priv->regmap, IPROC_REGCTL2,
561 				IPROC_ADC_AUXIN_SCAN_ENA, 0);
562 	if (ret) {
563 		dev_err(&pdev->dev, "failed to write IPROC_REGCTL2 %d\n", ret);
564 		return ret;
565 	}
566 
567 	ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno,
568 				iproc_adc_interrupt_handler,
569 				iproc_adc_interrupt_thread,
570 				IRQF_SHARED, "iproc-adc", indio_dev);
571 	if (ret) {
572 		dev_err(&pdev->dev, "request_irq error %d\n", ret);
573 		return ret;
574 	}
575 
576 	ret = clk_prepare_enable(adc_priv->adc_clk);
577 	if (ret) {
578 		dev_err(&pdev->dev,
579 			"clk_prepare_enable failed %d\n", ret);
580 		return ret;
581 	}
582 
583 	ret = iproc_adc_enable(indio_dev);
584 	if (ret) {
585 		dev_err(&pdev->dev, "failed to enable adc %d\n", ret);
586 		goto err_adc_enable;
587 	}
588 
589 	indio_dev->name = "iproc-static-adc";
590 	indio_dev->dev.parent = &pdev->dev;
591 	indio_dev->dev.of_node = pdev->dev.of_node;
592 	indio_dev->info = &iproc_adc_iio_info;
593 	indio_dev->modes = INDIO_DIRECT_MODE;
594 	indio_dev->channels = iproc_adc_iio_channels;
595 	indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels);
596 
597 	ret = iio_device_register(indio_dev);
598 	if (ret) {
599 		dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret);
600 		goto err_clk;
601 	}
602 
603 	return 0;
604 
605 err_clk:
606 	iproc_adc_disable(indio_dev);
607 err_adc_enable:
608 	clk_disable_unprepare(adc_priv->adc_clk);
609 
610 	return ret;
611 }
612 
613 static int iproc_adc_remove(struct platform_device *pdev)
614 {
615 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
616 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
617 
618 	iio_device_unregister(indio_dev);
619 	iproc_adc_disable(indio_dev);
620 	clk_disable_unprepare(adc_priv->adc_clk);
621 
622 	return 0;
623 }
624 
625 static const struct of_device_id iproc_adc_of_match[] = {
626 	{.compatible = "brcm,iproc-static-adc", },
627 	{ },
628 };
629 MODULE_DEVICE_TABLE(of, iproc_adc_of_match);
630 
631 static struct platform_driver iproc_adc_driver = {
632 	.probe  = iproc_adc_probe,
633 	.remove	= iproc_adc_remove,
634 	.driver	= {
635 		.name	= "iproc-static-adc",
636 		.of_match_table = of_match_ptr(iproc_adc_of_match),
637 	},
638 };
639 module_platform_driver(iproc_adc_driver);
640 
641 MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
642 MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
643 MODULE_LICENSE("GPL v2");
644